docs: def jsonset(self, name, path, obj, nx=False, xx=False):
          """
          Set the JSON value at key ``name`` under the ``path`` to ``obj``
          ``nx`` if set to True, set ``value`` only if it does not exist
          ``xx`` if set to True, set ``value`` only if it exists
          """
          pieces = [name, str_path(path), self._encode(obj)]
  
          # Handle existential modifiers
          if nx and xx:
              raise Exception('nx and xx are mutually exclusive: use one, the '
                              'other or neither - but not both')
          elif nx:
              pieces.append('NX')
          elif xx:
              pieces.append('XX')
          return self.execute_command('JSON.SET', *pieces)